The interatomic distance between the different atoms of PEG solid state M = 200 and 1000.

rm: Single bond length of Carbon – Carbon.
r′m: Single bond length of Carbon –Oxygen.
r’‘m: Double bond length of Carbon – Carbon.
rm/r1: Geometrical factor.
The absence of √2 diameter and presence of the geometrical factor corresponds to ∼√3 and ∼2 diameter demonstrates the presence of an irregular unit cell with icosahedral symmetry (Frank unit) in solid state PEG.
The interatomic distance between the different atoms of PEG solid state M = 200 and 1000.

$r_m$：碳-碳单键键长。$r'_m$：碳-氧单键键长。$r''_m$：碳-碳双键键长。$r_m/r_1$：几何因子。既无√2直径特征且几何因子对应~√3与~2直径的现象，证明固态聚乙二醇（PEG）中存在具有二十面体对称性的不规则晶胞（弗兰克晶胞，Frank unit）。分子量$M=200$与$1000$的固态聚乙二醇中不同原子间的原子间距。